The Yamaha FZ typically comes with a front tire size of 100/80-17. While it is technically possible to replace it with a 90/90-17 tire, there are a few considerations to keep in mind:
Size Difference: The 90/90-17 tire has a narrower width and slightly smaller diameter compared to the stock 100/80-17 tire. This change in size can affect the handling characteristics of the motorcycle. The narrower tire may result in reduced stability, especially during high-speed cornering.
Ground Clearance: Switching to a smaller tire size may affect the ground clearance of the motorcycle. The reduced tire diameter could lead to the bike sitting lower, potentially causing clearance issues when going over bumps or uneven surfaces.
Speedometer Accuracy: Changing the tire size can also affect the accuracy of the speedometer. The smaller diameter of the 90/90-17 tire may cause the speedometer to read higher speeds than you are actually traveling.
It is generally recommended to stick with the manufacturer's recommended tire size for your motorcycle. The tire size specified by Yamaha for the FZ is chosen to provide the best balance of performance, handling, and safety. If you still wish to make the change, it is advisable to consult with a knowledgeable mechanic or a Yamaha dealer to ensure that it is compatible with your specific model and to address any potential issues that may arise.